Recent testing of Lake Michigan water has found pharmaceutical byproducts, raising concerns about the potential health threats to wildlife and to anyone getting their drinking water from the Great Lakes.

A new Alliance report calls for more research into the long-term effects of drugs in drinking water and points out the absence of tools available to limit their entrance into the lakes.

Low levels of cotinine -- a nicotine byproduct, and the cholesterol-modifying drug gemfibrozil are among the pharmaceutical compounds scientists have found in Lake Michigan water to date.

Though many experts say the levels are too low to show immediate effects on human health, scientists acknowledge they know little about the long-term effects of these drugs on people and how they might degrade or interact with other chemicals in the water.

“Broader use of pharmaceuticals and growing knowledge of the health effects from their chemical byproducts make drug pollution an emerging concern,” said Lyman Welch, Alliance Water Quality Program manager and lead author of the report. “As we learn more about what dangers these drugs pose, we have to be ready to take precautionary steps to limit the amount that passes into the Great Lakes every day.”

Although reports of drugs in drinking water date back to the 1970s, a 2002 U.S. Geological Survey report was the first national examination of emerging contaminants in U.S. streams. Testing revealed a broad range of chemicals, including human and veterinary drugs, hormones, plasticizers, insecticides and fire retardants.

Noting some of the Great Lakes take up to 100 years to flush out pollutants, Welch said the drugs flowing into the world’s largest surface freshwater system today will remain there for generations.

Researchers worry about the threat to human health from long-term, low-level exposure to pharmaceuticals – in particular hormones and other chemicals that signal cell changes -- as these are designed to work in the body at low concentrations.

More recent USGS research has identified endocrine impacts – or disruption of the body’s hormonal system -- on aquatic health. Studies of the effects of endocrine-disrupting chemicals from wastewater treatment effluent on fish found altered reproductive organs ranging from reduced size to cancerous to some fish that displayed male and female characteristics.

The U.S. Environmental Protection Agency said last month it will soon begin screening to determine whether some chemicals found in drinking water are affecting endocrine systems in people and animals.

“We join the Alliance in calling for more research into the impacts of pharmaceutical pollution on human and environmental health,” said Scott Cassel, executive director of the Product Stewardship Institute. “At the same time, properly disposing of unused and expired medicines is one approach that can reduce those impacts now.”

The drug industry says the vast majority of drugs enter waterways via patient excretions, and secondarily by disposal in the garbage or flushing down the toilet. Drugs purchased for use by people or animals enter waterways via various pathways: in treatment plant and septic system effluent, runoff from uncontrolled landfills, industrial discharges, commercial animal feeding operations, and manure applications.

The report says sewage treatment plants and current laws are ill-suited to address the emerging problem of pharmaceutical pollution, which has come to light as water quality monitoring technology has become better at detecting lower contaminant levels.

Treatment plants aren’t designed to remove such pollutants, and attempts to collect and dispose of unwanted medications safely and easily are hindered by federal drug enforcement and hazardous waste disposal laws that don’t take pharmaceutical waste into account.

Past U.S. efforts to reduce pharmaceutical pollution have emphasized collecting unused medications. Welch said the Alliance is now calling for research into technologies to address drug pollution at the treatment plant stage, and is focusing on national efforts to reduce such pollution at the design and prescription stages. The Alliance has connected with efforts at the national level through a partnership with the Product Stewardship Institute.

“Properly disposing of unused and expired medicines is an easy step everyone can take to stop this pollution at the source,” said Welch. “But the onus will fall to health care providers, drug companies and sewage plant operators to take measures now to protect our public drinking water supplies from pharmaceutical pollution.”

The Searle Funds at The Chicago Community Trust provided financial support for this report.